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Submitted by ON4AVJ on Mon, 01/12/2008 - 11:45

These pages are meant to inform you on the VHF-UHF-SHF &
Microwaves DX activity in Belgium and Europe. You will find logs from ON stations,
planned DX-expeditions and their results. If you have information please send a mail to
vhf [at] uba [dot] bePhotos and sound files are also welcome.

For the past few weeks many 144MHz meteor scatter enthusiasts have been complaining of interference from AFSK packet transmissions. As a 144MHz DX enthusiast, in addition to being VHF manager I took an interest and started monitoring.

The transmissions on 144.390MHz FM AFSK occur at regular intervals, mostly on Northerly headings. The transmissions fill about 15KHz of spectrum on the waterfall display of a SDR receiver.

Because of the inclined orbit Northern European amateurs get a longer pass than those in the US which means that there is a burst every minute for a pass lasting up to about 12 minutes, repeating every 110 minutes orbit time. Whilst that is not continuous QRM one pass is enough to cause a meteor scatter QSO on 144.390 +/- 6KHz to fail if they coincide.

Find hereby the text of AMSAT-NA, published in their weekly bulletin:

PCSAT Default Beacon Transmissions on 144.390 MHz

An FM APRS signal has been received in England causing interference to the MGM frequency and weak-signal Meteor Scatter (MS) operation which is just below 144.390 MHz. A MS DXpedition was disrupted by such activity earlier in the month and interference has been occurring at various times since.

Bob Bruninga, WB4APR, explains that the beacon was planned over 15 years ago for operation only when PCSAT is over North America based on published band plans at that time. Now, after 14 years on orbit, the ability to turn that backup beacon off has been lost.

PCSAT (now 14 years old) had a backup fail-safe beacon on 144.390 that would activate after any unknown spacecraft reset to give a backup comm link in case the primary 145.825 channel died. Being on the North American APRS frequency with hundreds of IGates there would always be at least one that would hear this "emergency call home" from PCSAT even though the channel is generally saturated. It worked.

The problem is, that now PCSAT resets on every orbit due to negative power budget and so, on every orbit that beacon comes back on. Even if we did get a command up to reset it, that setting would last only 15 minutes to the next eclipse.

We learned our lesson! That was our FIRST amateur satellite and we sure learned NOT to use a "connected-packet-command link" that needs ACKS and Retries and logon passwords just to LOGON before you can even send a SHUTUP command. All our satellites since, operate without the multiple Send, connect, ACK, retry, ACK, command, ACK overhead… just to get one command understood. Now, only the receiver on the spacecraft has to be functional to command it to silence in a single packet. But too late for PCSAT.

Expedtion to ZB

02-08-2015

Submitted by: ON4AVJ

From August 10th to August 14th ON7EQ and ON5AEN will be active from ZB in IM76 square.

Activation of the Gibraltar Radio Amateur Society club station ZB2BU in Meteor Scatter on 70 Mhz and 144 MHz (as ZB2/ON7EQ) concentrated during Perseid shower, around August 13th.

More info - like frequencies, sequences etc… - will be released later via respective ON4KST chat rooms.

Meanwhile, already prepared some theoretical range prediction. According to our spot where we have chosen to set up the station and the excellent take-off in the NE quadrant, we expect a range like depicted on the map - as you can see ON will be ideally within reach!

With special thanks to the GARS for their support and interest in this Meteor Scatter activation.

73 and looking forward to cu in MS!

Jean-Jacques ON7EQ
Hans ON5AEN

New ARI EME Trophy

16-04-2015

Submitted by: ON4AVJ

ARI is proud to invite you all to take part to the New ARI EME Trophy.Full rules are here.
The first period is on April 25-26th.

Best 73’s Alex IV3KKW

New spectrum for digital experiments in UK

02-04-2015

Submitted by: ON4AVJ

Ofcom have agreed the use of 70.5 MHz to 71.5 MHz by radio amateurs for digital experimentation.
Use will be permitted only via a Special Research Permit and further details of the application process will be published in due course.

For information, the following conditions will apply:

Access to this part of the spectrum will be authorised under a Notice of Variation, time-limited to 12 months and available to Full Licence holders only.

Ofcom will retain the right to reallocate Amateur Radio spectrum at 70.5 – 71.5MHz should there be a demand for this part of the spectrum from Business Radio and/or other or new services. In the event of this happening, Ofcom will not consult on this decision. However, Ofcom will provide Amateur Radio users with 12 months’ notice before such reassignment and this notice period will be publicised on the Ofcom website.

Amateur Radio use of this spectrum will be permitted on a non-protection, non-interference basis. Please note that if use is shown to cause interference, the spectrum will be removed with immediate effect

Permission will be subject to a geographical restriction and only granted for use in England, Guernsey, Isle of Man, Jersey, Northern Ireland and Wales. (There is legacy use of the spectrum by the Scottish Government which precludes licensing for Amateur Radio).

Note that in a similar manner to 146-147MHz, international coordination is likely to be required as use must be compliant with the level published in the Harmonised Calculation Method (HCM) Agreement of +6dBuV/m.

73
John - RSGB VHF Manager

23cm EME Contest

29-12-2014

Submitted by: ON4AVJ

Hi All,

I enjoyed the nice activity on 23 cm during the ARRL contest, with a good mix of CW, JT and SSB QSOs. Many stations were contacted on both CW and JT modes. After cleaning all the dupes, I ended with a total of 86 QSOs and 33 multipliers. Was also very pleased to QSO the PZ5EME expedition on 13 and 23 cm for a new DXCC and first from ON. Their 1.5 m dish was producing a very nice signal on both bands!

HNY
Eric
ON5TA
3.6 m mesh dish
200 W at feed

UBA VHF Summer Cup

29-06-2014

Submitted by: ON4AVJ

In summer it is a good time to experience the joie of DX on VHF. There fore the UBA created the VHF DX summer cup. With this cup we want to promote VHF DXing. More info here.